Luminaire with long chains of lower power LEDs and multiple on-board LED drivers

ABSTRACT

A luminaire may include an input connection that receives AC line voltage, one or more chains of LEDs, and one or more drivers for driving each chain of LEDs, all within a housing, which may be in the form of a canopy. Each chain of LEDs may contain at least 36 LEDs connected in series. Each LED may have a power rating of no more than 1 watt and may be oriented to direct light outside of the housing when illuminated. Each driver may receive power that is extracted from AC line voltage connected to the input connection and provide one or more outputs that drive at least one of the chains of LEDs.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 13/828,446, entitled “Luminaires and LuminaireMounting Structures,” filed Mar. 13, 2014. The entire content of thisapplication is incorporated herein by reference.

BACKGROUND

1. Technical Field

This disclosure relates to luminaires, including outdoor lightingcanopies that are driven by AC line voltage and include multiple LEDs.

2. Description of Related Art

Outdoor canopy lighting may utilize multiple LEDs mounted within ahousing to provide needed lighting. These LEDs may need a driver togenerate the regulated current that is needed to drive the LEDs.

A single large driver is usually mounted outside of the luminairehousing to drive the LEDs. This has been done because of concern overthe effect of noise generated by the LEDs within the housing on theoperation of the driver, because of the absence of strong surgeprotection inside of the luminaire housing to protect the driver fromsurges in line voltage, and to make it easy to replace components in thedriver that sometimes fail, such as electrolytic capacitors. However,positioning the driver outside of the canopy housing may require aseparate housing to house the driver. This may add to costs and requireadded space for the separate housing

Drivers have also been designed to drive a chain of series-connectedLEDs in sub-chain steps that correspond to the amplitude of the linevoltage. Typically, the chain and each of its sub-steps consist of asmall number of high power LEDs to minimize costs and maximizedurability. However, high power LEDs can be less efficient and using asmall number can result in spotted lighting patterns.

SUMMARY

A luminaire may include an input connection that receives AC linevoltage, one or more chains of LEDs, and one or more drivers for drivingeach chain of LEDs, all within a housing. Each chain of LEDs may containat least 36 LEDs connected in series. Each LED may have a power ratingof no more than 1 watt and may be oriented to direct light outside ofthe housing when illuminated. Each driver may receive power that isextracted from AC line voltage connected to the input connection andprovide one or more outputs that drive at least one of the chains ofLEDs.

Each chain of LEDs may include multiple sub-chains of LEDs connected inseries, each sub-chain containing multiple LEDs in series. Each of theLED drivers may provide a separate output that drives at least one ofthe chains of LEDs at each of the junctions between each of itssub-chains in a stepped sequence that is a function of the level ofvoltage of the power that is received by LED driver.

At least one sub-chain within each chain may include at least 12 LEDs.

No sub-chain within each chain may include less than 6 LEDs.

The outputs of at least two of the LED drivers may be connected inparallel.

The outputs of at least one of the LED drivers may be connected to oneof the chains of LEDs and the outputs of at least one other of the LEDdrivers may be connected to another of the chains of LEDs.

The input connection, the chains of LEDs, and the LED drivers may all beon a single printed circuit board.

Each chain of LEDs may have at least 48 LEDs.

The power rating of each LED may be no more than 0.6 watts.

The housing may form a canopy light.

These, as well as other components, steps, features, objects, benefits,and advantages, will now become clear from a review of the followingdetailed description of illustrative embodiments, the accompanyingdrawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

The drawings are of illustrative embodiments. They do not illustrate allembodiments. Other embodiments may be used in addition or instead.Details that may be apparent or unnecessary may be omitted to save spaceor for more effective illustration. Some embodiments may be practicedwith additional components or steps and/or without all of the componentsor steps that are illustrated. When the same numeral appears indifferent drawings, it refers to the same or like components or steps.

FIG. 1A is a bottom-side perspective view of a luminaire in accordancewith the present disclosure;

FIG. 1B is a top-side perspective view of the luminaire depicted in FIG.1A with driver box and stem;

FIG. 1C is an exploded view of the luminaire depicted in FIG. 1A withdriver box, stem and gasket;

FIG. 2A is a bottom-side perspective view of a housing of the luminairedepicted in FIG. 1A;

FIG. 2B is a top-side perspective view of a housing of the luminairedepicted in FIG. 1A with the lens frame shown for context;

FIG. 3A is a top-side perspective view of a lens frame of the luminairedepicted in FIG. 1A;

FIG. 3B is an outtake of a portion of the lens frame of FIG. 3A, with agasket and adhesive sealant not depicted in FIG. 3A;

FIG. 4A is a cross-section of a portion of the luminaire depicted inFIG. 1A;

FIG. 4B is a different cross-section of a portion of the luminairedepicted in FIG. 1A;

FIG. 4C is yet another different cross-section of a portion of theluminaire depicted in FIG. 1A;

FIG. 4D is a cross-section of a portion of the luminaire depicted inFIG. 1A showing a greater width of the luminaire than FIGS. 4A-C;

FIG. 4E is a cross-section of the housing stem of the luminaire depictedin FIG. 1A populated with wiring and breathing tube;

FIG. 5A is a bottom side view of the driver box and driver box stemdepicted in FIG. 1B;

FIG. 5B is an exploded view of the luminaire depicted in FIG. 1A and thedriver box and gasket depicted in FIG. 1C in the context of installationto a structure;

FIG. 6 is a bottom side view of the printed circuit board of theluminaire depicted in FIG. 1A;

FIG. 7A is a bottom-side perspective view of the luminaire depicted inFIG. 1A mounted in a mounting structure;

FIG. 7B is a perspective cross-sectional view of the luminaire andmounting structure depicted in FIG. 7A;

FIG. 7C is a top side view of the luminaire and portions of the mountingstructure depicted in FIG. 7A;

FIG. 7D is a cross-sectional view of portions of the luminaire andmounting structure depicted in FIG. 7A;

FIG. 7E is a perspective view of a locking wing of the mountingstructure depicted in FIG. 7A; and

FIGS. 7F and 7G are perspective views of optional mounting structureextensions of the mounting structure depicted in FIG. 7A.

FIG. 8 illustrates an example of a circuit that includes a driver and along chain of low power LEDs that may be driven by the driver, all ofwhich may be on a single circuit board within an outdoor canopy light.

FIG. 9 illustrates an example of a circuit that includes multipledrivers and a long chain of low power LEDs that may be driven by themultiple drivers while their outputs are connected in parallel, all ofwhich may be on a single circuit board all within an outdoor canopylight.

FIG. 10 illustrates an example of a block diagram of an outdoor canopylight that may use a single D.C. power supply to supply power to one ormore drivers that each drive one or more long chains of low power LEDs,each LED chain and associated driver(s) being in a different quadrant ofan outdoor canopy light.

FIG. 11 illustrates an example of one quadrant of a long chain of lowpower LEDs on a single circuit board.

FIG. 12 illustrates an example of a single circuit board that may beplaced within an outdoor canopy light that includes four quadrants, eachwith a long chain of low powered LEDs and an associated power supply anddrivers.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Illustrative embodiments are now described. Other embodiments may beused in addition or instead. Details that may be apparent or unnecessarymay be omitted to save space or for a more effective presentation. Someembodiments may be practiced with additional components or steps and/orwithout all of the components or steps that are described.

While the preferred embodiment uses light emitting diodes (“LEDs”) aslight sources, other light sources may be used in addition to LEDs orinstead of LEDs within the scope of the present disclosure. By way ofexample only, other light sources such as plasma light sources may beused. Further, the term “LEDs” is intended to refer to all types oflight emitting diodes including organic light emitting diodes or“OLEDs”.

While the luminaire depicted in the Figs. is generally applicable to anyapplication that would benefit from indoor or outdoor area lighting, itis well-suited, in one example, for application to canopies and the likesuch as those used at petroleum refill stations. In other applications,luminaires and mounting structures disclosed herein are applicable tosoffits or ceilings.

FIGS. 1A and 1B depict bottom-side and top-side perspective views of aluminaire 100, in accordance with the present disclosure, which is alow-profile luminaire capable of providing proper light distribution andhaving a minimum number of parts. The luminaire 100 comprises a housing102, a circuit board 104 populated with light sources 106 such as LEDs,a plurality of screws 108, a lens 110, a gasket 112 and a lens frame114. The circuit board 104 can be any known circuit board for properlyarranging the light sources 106 and, in one embodiment, can be a printedcircuit board (“PCB”). For the sake of simplicity, circuit board 104will be referred to herein as a PCB, but it will be understood that anytype of circuit board is suffice.

The overall shape of the luminaire 100 is depicted as substantiallysquare with rounded corners, but other shapes are contemplated asoperating within the scope of this disclosure. By way of example only,rectangular, circular and triangular are all contemplated. Because theoverall shape of the luminaire 100 is dictated in the depictedembodiment by the shape of the housing 102 and the lens frame 114, theshape of the housing 102 and lens frame 114 are likewise contemplated ashave these exemplary shapes or others.

The housing 102 comprises a plate 116, a perimeter 118 and a wall 120between the face 116 and the perimeter 118. The perimeter 118 extendsabout the perimeter of the housing and thus takes the shape of thehousing, which in the depicted embodiment, is square with roundedcorners, as discussed above. The perimeter 118 defines a front face 118a and a rear face 118 b. The front face 118 a of the perimeter 118extends from an inner edge 118 c to an outer edge 118 d which definesthe outermost perimeter of the housing 102. The perimeter inner edge 118c defines the downward most facing portion of the housing 102. The frontface 118 a of the perimeter 118 extends from the perimeter inner edge118 c to the perimeter outer edge 118 d forming a curvilinear front face118 a. In the depicted embodiment, the curvilinear front face 118 ainitially extends outward form the inner edge 118 c in straighthorizontal manner, and then curves upward with an ever-increasing radiusof curvature to the perimeter outer edge 118 d. Other curvilinear shapesare contemplated as falling within this disclosure. By way of exampleonly, the front face could extend horizontally to a 90° edge, which thenextends upward to the outer edge.

References herein to upward and downward orientation are with referenceto the depicted embodiments in which the luminaire 100 is mounted to theunderside of a flat structure (such as a ceiling or a canopy) and arefor purposes of conveying a description of the elements of thedisclosure, but are in no way intended to be limiting. In application,upward can be reoriented downward and downward can be reoriented upward.

The housing perimeter 118 preferably defines one or more locator grooves122 extending from the perimeter front face upward into the perimeterwith a locator groove wall 122 a to a locator groove base 122 b that isflat in the depicted embodiments, but can vary, extending horizontally.The locators grooves 122 receive locator bosses 140 on the lens frame114 to assist in properly locating the lens frame 114 on the housing 102and, separately, to accommodate a boss from the lens frame 114 which canreceive a mounting screw 134 from the groove base 122 b, which willremain hidden from sight to persons viewing the bottom of the luminaire100, in the depicted embodiment. FIG. 4B depicts a cross-section of aportion of the luminaire 100 through a locator groove 122, acorresponding locator boss 140 and mounting screw 134.

In the depicted embodiment, the luminaire 100 defines two locatorgrooves 122 on each of the four sides defining the square shape of theluminaire 100. Greater or fewer locator grooves 122 are contemplated.For example, if the locator grooves 122 are used purely for locating thelens frame 114 on the housing 102, then one, or two would suffice.Alternatively, an embodiment of the luminaire 100 is contemplated withno locator grooves 122. If, however, the locator grooves 122 are used toaccommodate a boss to facilitate mounting the housing 102 to the lensframe 114 by screw, or the like, then the number and location of thelocator grooves 112 will be dictated by the size and weight of the lensframe 114 in order to properly secure the lens frame 114 to the housing102 with sufficient sealing there between, if desired, as discussedbelow.

The housing plate 116 extends across the housing to fill in the areasurrounded by the housing perimeter 118. The housing wall 120 extendsdownward from the housing plate 116 just inward of the housing perimeter118 to a distal end 120 a and about the entire housing plate 116 asdepicted in FIG. 2A. The housing wall 120 does not extend as far down asthe inner edge of the perimeter 118. Rather, the housing wall 120extends downward far enough to engage the gasket 112 located in the lensframe 114 as shown in FIGS. 4A-4D and discussed below. In this manner,the wall 120 deforms the gasket 112 forming a vapor and moisture barrierthere between. Because the wall 120 and gasket 112 extend about theentire luminaire 100 just inward of the perimeter 118, a vapor andmoisture barrier is formed between areas inward of the wall 120 (e.g.the PCB) and areas outward of the wall 120. This construction forms abarrier against vapor and moisture that might otherwise ingress betweenthe housing 102 and lens frame 114. The housing wall 120 can takedifferent forms as seen in FIGS. 4A-4D in order to minimize weight andmaterial while still creating sufficient deformation of the gasket 112to create desired vapor and moisture barrier.

The housing plate 116 has a front face 116 a and a rear face 116 b. Thehousing plate front face 116 a is substantially flat, extending acrossand filling in the perimeter 118, with the exception of a plurality ofmounting holes 124 defined therein and a spacer boss 126 surrounding andextending each mounting hole 124 out beyond the housing plate front face116 a. Each spacer boss 126 comprises a cylindrical wall extendingdownward from the housing plate front face 116 a to a distal end 126 aand configured so that an inner wall of the spacer boss 126 continuesthe inner wall of the corresponding mounting hole 124 so that the spacerboss 126 effectively extends the depth of the mounting hole 124 to adepth B. In the depicted embodiment, the spacer boss distal end 126 asits approximately even with a front face 104 a of the PCB (as depictedin FIGS. 4A and 4D), thus acting to space the head of the screws 108 adistance approximately equal to the thickness of the PCB, shown asdistance C in FIG. 4D, to the PCB front face 104 a. In one exemplaryembodiment, distance B can be 0.125 inches, where the distance C can be0.047 inches. In another exemplary embodiment, height of the spacerbosses 126 is just short of the thickness of the PCB 104 so that thescrews 108 not only hold the PCB 104 from falling off the housing 102,but also hold it steady, preventing rattle of the PCB 104 and creating aheat transfer connection between the PCB 104 and the housing 102 causingthe housing 102 to act as a heat sink for the PCB 104 and the LEDs 106mounted thereon. These objectives are enhanced when the screws 108 areconstructed of a pliable material, as discussed below. The height of thespacer bosses 126 could be 0.002 inches shorter than the thickness ofthe PCB 104 in one embodiment. Other dimensions are contemplated to meetthese objectives.

In an alternative embodiment, no spacer bosses 126 are employed.However, the spacer bosses 126 provide two advantages. First, the spacerbosses 126 reduce assembly time by allowing screws 108 to be driven intothe mounting holes 124 without regard for when they reach the PCB 104.Without the spacer bosses 126, advancing the screws 108 would beconducted with concern about advancing them too far or with too muchpower, either of which might damage the PCB 104. The spacer bosses 126obviate that concern by allowing the screws 108 to be advanced to thespacer boss distal end 126 a as quickly and efficiently as possible.This ease of securing the screws 108 to the housing 102 without damagingthe PCB 108 is further advanced by using screws 108 of a pliablematerial such as, by way of example only, nylon. Use of such pliablescrews 108 will allow the screws 108 to be advanced without regard forexactly when advancement need stop. That is, over advancing the screws108 will not “strip” the mounting holes 124 or damage the screws 108 toan extent such to prevent them from holding the PCB 104 to the housing102. Instead, by using screws 108 of a pliable material, over advancingthe screws will slightly deform the threads of the screws 108, but notso much as to prevent the pliable threads of the screws 108 fromgrasping the inside of the mounting holes 124.

Moreover, in the depicted embodiment, the inner wall of the mountingholes 124 is straight (i.e. is not threaded). This further limitsproduction costs by removing the need to tap the mounting holes 124 orcreate a complicated mold having reliable threads in the mounting hole124. Additionally, using straight mounting holes 124 actually allowsshallower mounting holes 124 because the use of a typically tap tocreate the threads in a mounting hole requires a certain depth in orderto facilitate the tapping. Using straight holes eliminates the need tobe able to tap the mounting holes 124, thus allowing shorter mountingholes 124 than could otherwise be used. In one exemplary embodiment, thedepth B of the mounting holes 124 is 0.125 inches. Furthermore, by usingthe spacer bosses 126 to extend the wall of the mounting hole 124 out tothe face of the PCB 104, the depth of the mounting hole 124 is movedinto the luminaire 100, reducing the distance that the mounting hole 124need extend toward the housing plate rear face 116 b, thus allowing athinner overall luminaire 100. Moreover, using pliable screws 108 instraight mounting holes 124 further reduces, or eliminates, thelikelihood of damaging the screws 108 by over advancement.

The second advantage provided by the spacer bosses 126 is their inherentability to reduce tolerances in the stack of elements (housing 102, PCB104, screws 108, lens 110 and lens frame 114) contributing to the overall height of the luminaire 100, and thus its low-profile. As discussedin greater detail below, tight stack of these element contributes to thelow-profile. The ability to advance the screws 108 against the spacerbosses 126 without exception so as to limit the tolerances necessary andcontribute to an overall low profile. The additional cost of thesespacer bosses is negligible in an embodiment where the housing is castfrom a material (e.g. aluminum).

The housing plate rear face 116 b is also substantially flat, with theexception of a matrix of interconnecting walls 128 extending from therear face 116 b a short distance off that face. This matrix 128increases the overall rigidity of the plate 116 and thus the housing102. The matrix 128 also provides additional surface area on the rear ofthe housing 102 to increase the ability of the housing to dissipate heatwhen any of the matrix 128 is exposed to ambient air. The matrix 128also assists in providing surface contact with structure to which thehousing is mounted when that structure has surface irregularities (i.e.is not flat). This surface contact can also be helpful in directing heataway from the luminaire 100 in installations such as a petroleum refillstation canopy which is constructed of sheet metal and much of the sheetmetal, except where contacted by the housing, is exposed to ambient airto facilitate transferring to the surrounding air, some of the heatgenerated by the light sources or utilities for powering the lightsources.

The matrix 128 may optionally include bosses 130 at the bottom of themounting holes 124. These bosses 130 provide additional thickness toaccount for molding irregularities.

In the depicted embodiment, the housing perimeter rear face 118 bfollows the curvature of the housing perimeter front face 118 a for themost part. A cross-section of one embodiment is depicted in FIG. 4C.This embodiment keeps the perimeter thin and reduces material usagewhile the curvature provides structural rigidity. Other shapes andthicknesses are contemplated. The housing perimeter rear face 118 b alsoincludes the backside of the locator groove wall 122 a and locatorgroove base 122 b protruding therefrom.

As discussed above, one or more of the locator groove bases 122 b definea screw aperture 132 to accommodate a screw 134 to extend through thehousing 102 and into the lens frame 114 to secure the lens frame 114 tothe housing 102. In the depicted embodiment, the screw 134 enters fromthe housing and extends into the lens frame 114 so as to not be visiblefrom the front side of the luminaire 100. A cross-section of thisembodiment is depicted in FIG. 4B. Other embodiments are contemplated.

In order to minimize the number of screws 134 necessary for assembly andminimize the corresponding assembly steps, one or more fins 136 mayextend across the housing perimeter rear face 118 b to fill in the backside of the housing perimeter 118 curvature and provide the housingperimeter 188 with added structural rigidity. In the depictedembodiment, each side of the square housing comprises a single such fin136 between the two screws 134 and one such fin 136 at each roundedcorner of the housing perimeter 118. A cross-section of this embodimentis depicted in FIG. 4A. Other embodiments are contemplated.

The lens frame 114 defines a front face 114 a and a rear face 114 b andcomprises a lens frame perimeter 136 at the outermost perimeter of thelens frame 136 and a trough 138 defined by an inner trough wall 138 aand outer trough wall 138 b. The contour of rear face 114 b of the lensframe perimeter 136 follows the contour of the housing perimeter frontface 118 a, extending to a distal end 136 a that lies in approximatelythe same horizontal plane as the housing perimeter outer edge 118 d.References herein to a “horizontal” plane are by way of describingrelationships between elements and portions of elements in the disclosedluminaire 100 and the term “horizontal” is used because the luminaire100 is described as being mounted to a ceiling or the like. Use of theterm “horizontal” is not limiting on the luminaire 100 as it could berotated to be mounted in any orientation. By extending the lens frameperimeter distal edge 136 a to the housing perimeter outer edge 118 d,the lens frame can cover the housing perimeter 118 from view to providethe luminaire 100 a simple and elegant aesthetic look as seen in FIG.1A. One of more locator boss 140 extends rearward from the lens framerear face 114 b into the curvature defined by the lens frame perimeter136. As described above, the locators grooves 122 of the housing 102receive the locator bosses 140 to assist in properly locating the lensframe 114 on the housing 102 and, separately, to receive the mountingscrew 134, which will remain hidden from sight to persons viewing thebottom of the luminaire 100, in the depicted embodiment. FIG. 4B depictsa cross-section of a portion of the luminaire 100 through a locatorgroove 122, a corresponding locator boss 140 and mounting screw 134. Thelens frame 114 is oriented vertically at the distal edge 136 and thencurves downward and inward with an ever increasing radius of curvaturethe farther it is from the distal edge 136 until it is orientedapproximately horizontal where it is adjacent to the housing perimeterinner edge 118 c.

A base 138 c of the lens frame trough 138 continues to extend inwardfrom the lens frame perimeter 136 horizontally and seamlessly from thelens frame perimeter 136. Other embodiments are contemplated. The lensframe trough inner trough wall 138 a then extends vertically to definethe lens frame innermost perimeter which defines a lens frame aperture142 through which light emitted by the light sources 106 passes to leavethe luminaire 100.

Gasket 112 is located about the perimeter of the trough outer wall 138 b(depicted in FIG. 3B and FIGS. 4A-4D, but not FIG. 3A), which holds thegasket 112 in place during assembly. When the housing 102 and lens frame114 are brought into alignment with, and secured one to the other, thehousing wall 120 contacts and deforms the gasket 112. In the deformedstate, the gasket 112 forms a seal against ingress of vapor, moisture,water or dirt between the housing 102 and the lens frame 114. The gasket112 extends around the entire perimeter of the outer trough wall 138 band the housing wall 120 extends around the entire housing 102 such thatthe seal formed between the housing wall 120 and the gasket 112 extendsabout the entire perimeter of the PCB 104 preventing ingress of vapor,moisture, water or dirt between the housing 102 and the lens frame 114that could reach the PCB 104 or other portions of the luminaire 100within that perimeter seal. In an alternative embodiment, a urethanesealant could be substituted for the gasket 112. For the sake ofefficiency, this urethane adhesive could be the same urethane adhesiveas used in the trough 138, as discussed below.

The trough inner wall 138 a extends upward a distance A (FIG. 4D) fromthe trough base 138 c to a distal end on which the lens 110 rests. Thelens 110 is sized so as to rest on the trough inner wall 138 a distalend and extend almost all of the way to the trough outer wall 138 b,leaving at least sufficient space there between to ease assembly. Thetrough outer wall 138 b extends upward from adjacent the lens frameperimeter 136 and upward beyond the lens 110. The trough inner wall 138a is therefore shorter than the trough outer wall 138 b. An adhesivesealant 144 is deposited into the trough 138 during assembly in a beadhaving a height sufficient so that when the lens 110 is placed on top ofthe bead, the lens 110 will deform the bead of adhesive sealant 144until the lens 110 contacts and rests on the tough inner wall 138 adistal end. The height of the trough inner wall 138 a is a height A, andis designed to prevent the lens 110 from squeezing all of the adhesivesealant 144 out from between the lens frame 114 and lens 110 by limitingthe distance between the lens 110 and the trough base 138 c to height A.In this manner, the deformed bead of adhesive sealant 144 will havesufficient height to provide adhesion between the lens 110 to the lensframe 114. In one exemplary embodiment, the height A is 0.094 incheswhen using a 0.225 inch diameter bead of a urethane adhesive(SikaTack®-Ultrafast, sold by Sika Corporation, in one embodiment). Inthis embodiment, it has been found that the bead compresses toapproximately the height A and approximately 0.425 inches, providingsufficient surface area to adhere to the lens 110. Other heights A, beaddiameters and adhesive sealants are contemplated.

As depicted in FIGS. 4A-4D, the lens 110 in the assembled luminaire 100,is held by inner trough wall 138 a and forced into contact with the headof the screws 108. In this depicted embodiment of the luminaire 100, thehead of one or more of the screws 108 is sized (height of D) tofacilitate this contact between the heads of the screws 108 and the lens110. This contact holds the screws 108 in the mounting holes 124 andeliminates the need for any holding force between the screws 108 and themounting holes 124 once the luminaire 100 is assembled. The need foronly short term holding force between the screws 108 and mounting holes124 can further reduce the requirements of the mounting hole 124 and thescrews 108 allowing them to be even shorter and allowing an even thinneroverall luminaire. The short term requirement for this holding force canalso reduce the requirements of screws 108, reducing the overall cost ofthe luminaire 100. In one exemplary embodiment, the height of the screwsis just sufficient to prevent the screws 108 from backing off the forcewith which they press on the PCB 104. In an alternative exemplaryembodiment, the lens 110 increases the force with which the screws 108press on the PCB 104. In one exemplary embodiment, the height D of thehead of such screws 108 is 0.190 inches. Alternative embodiments arealso contemplated in which the screw 108 is not held by the lens 110 orare rivets through the PCB 104 and through a hole (not depicted) in thehousing 102. Other attachment hardware is also contemplated.

The PCB 104 comprises a PCB front face 104 a populated with LEDs 106 anda PCB rear face 104 b. The PCB rear face 104 b is pressed into contactwith the housing 102 by the screw 108 to create sufficient contactbetween the PCB 104 and the housing 102 to allow the housing 102 to actas a heat sink, taking away heat generated by the LEDs 106 andassociated circuitry.

With the exception of the LEDs 106, the PCB front face 104 a is coveredwith a reflective coating or covering. In one exemplary embodiment, thePCB front face 104 a is covered with a white adhesive paper adhered tothe PCB front face 104 a. In another embodiment, the PCB front face 104a is covered with a sheet of reflective aluminum (not depicted). Thereflective coating or covering covers the PCB from view while, at thesame time, redirecting light off of the PCB front face 104 a rather thanabsorbing it. Many luminaires, especially those using LEDs, placereflectors or optics near the light sources to redirect light emittedfrom the light sources to travel out of the luminaire. When using thisreflective coating or covering discussed above, the luminaire of thepresent disclosure does not use any such reflectors or optics. Theabsence of reflectors and optics allows the distance between the PCB 104and the lens 110 to be set as low as desired, bounded only by the needto secure the PCB 104 to the housing 102. In this manner, the absence ofany reflectors or optics further contributes to a thin (i.e.low-profile) luminaire 100.

In order to further reduce the overall height of the luminaire 100, thelight sources are LEDs 106 comprised of 0.25 Watt LEDs rather thanlarger, more powerful LEDs. Historically, one challenge of using LEDsfor area lighting has been that LEDs have traditionally emittedinsufficient light to replace more conventional light sources such asincandescent or fluorescent. This deficiency has traditionally beenovercome by the use of a matrix of LEDs. However, as the acceptance ofLEDs for area lighting has become more accepted, technologies have beendriven to increase the lumen output LEDs. As the technologies haveadvanced in this manner, conventional thinking in the LED lightingindustry has been to use the biggest and brightest LEDs available forarea lighting. The luminaire 100 of the present disclosure takesadvantage of the advances in technology, but bucks traditional thinkingby using a larger number of smaller, low output LEDs 106 as opposed to alarger number of larger, higher lumen output LEDs. The use of thesesmaller, low-output LEDs 106 provides the luminaire 100 two advantages.

First, many manufacturers currently manufacture and sell 1 Watt LEDs.For example, Nichia sells the NS9W383 1 Watt LED. This 1 Watt LED has aheight of approximately 0.108 inches. Instead of using these, or other,1 Watt LEDs, the LEDs 106 used by the luminaire 100 are 0.25 Watt LEDs.In one exemplary embodiment the LEDs 106 are Nichia NS2W757A LEDs. MoreLEDs 106 are required to provide the luminaire 100 the same lumen outputthan would be necessary if the 1 Watt LEDs were used. However, the 0.25Watt LEDs 106 reduce the height of the LEDs by 0.086 inches, allowingfurther reduction in the overall height of the luminaire 100.

In one embodiment of the disclosed luminaire depicted in FIG. 6, the PCB104 is populated with 460 Nichia 0.25 Watt NS2W757A LEDs arranged in amatrix spacing them at a pitch of 0.625 inches. When driven at 530 mA,these 460 LEDs emit approximately 37 lumens each for a total ofapproximately 17,000 lumens. When driven at 650 mA, these 460 LEDs emitapproximately 44 lumens each for a total of approximately 20,240 lumens.

Second, it has been found that the larger number of lower Watt and lumenLEDs 106 provide a more even light distribution that is more pleasant tothe eye. This more even glow can be expressed as a ratio of the lumens(L) per LED 106 to the pitch (P) of the LEDs 106. In the embodimentsdisclosed in the preceding paragraph, each of the 460 LEDs are spaced ata pitch P of 0.625 inches. When these LEDs are driven at 530 mA theyproduce approximately 37 lumens each for a ratio of 59.2 lumens/inch.When these same LEDs are driven at 650 mA they produce approximately 44lumens each for a ratio of 70.4 lumens/inch. Other lumen outputs perchip and pitches are acceptable. It has been found that a P/L ratio ofbetween approximately 59.2 lumens/inch and approximately 70.4lumens/inch provide a combined even glow when the 0.25 Watt LEDs areilluminated. This ratio is contemplated as applicable to LEDs of othersmall wattage.

The accumulation of the above discussed advantages of the disclosedluminaire 100 result in an overall thin (i.e. low profile) luminaire100. With the height E between the rear of the housing 102 and thehousing plate front face 116 a (0.193 inches in one exemplaryembodiment) minimized to the thickness of a plate necessary for moldingthe mounting holes 124 in the housing plate front face 116 a and thematrix 128 on the housing place rear face 116 b, the height E can beless than 0.2 inches and it has been found that a height of 0.193 inchesis optimal. Furthermore, use of pliable screws 108, with straightmounting holes 124, spacer bosses 126, thin LEDs 106 and a lens frametrough 138 having an inner trough wall 138 a working in conjunction withthe screws 108 to precisely control the height of the lens 110 withrespect to the PCB 104 and the lowermost extremity of the lens frameaperture 142 creates a high precision, low tolerance stack of parts thatfacilitate a precisely thin luminaire 100 that eliminates the need forreflectors or optics thus further reducing the thickness of theluminaire 100. The height F between the housing plate front face 116 aand the lowermost extremity of the lens frame aperture 142 (0.510 inchesin one embodiment) is thus minimized and in conjunction with theminimized height E, provides an overall low profile, highly efficientluminaire 100. In the exemplary embodiment of height E being 0.193inches and height F being 0.510 inches, the total height of theluminaire is only approximately 0.703 inches and is facilitated by oneor more of the above discussed features.

The low height F, minus the low height C of the PCB 104 provides a verylow height between the base of the LEDs 106 and the lowermost extremityof the lens frame aperture 142 through which light rays emitted from theLEDs 106 escape the luminaire 100. This resulting low height allows mostof the lumens emitted from the LEDs 106 to escape the luminaire 100without need for reflectors or optics. In the example identified aboveusing 460 Nichia 0.25 Watt NS2W757A LEDs driven at 650 mA to emit atotal of 20,240 lumens, it has been found that of the 20,240 emittedlumens, 20,195 escaped the luminaire 100 in this configuration.

In one embodiment of the disclosed luminaire, a driver column 146extends upward from the rear of the housing plate 116. The driver column146 may be integral with the housing plate 146 or not integral. In thedepicted embodiment, the driver column 146 is integrally cast as part ofhousing 102. The driver column 146 comprises four wings 148 extendingradially from a central axis of the driver column 146. The driver column148 could comprise greater or fewer wings 148; three in one exemplaryembodiment. Each wing 148 extends upward from the housing plate 116,having opposing lateral walls 148 a and a circumferential wall 148 b atthe circumferential perimeter of the driver column 146. In the exemplarydepicted embodiment, the circumferential wall 148 b extendsapproximately tangential to the circumference of the driver column 146and the opposing lateral walls 148 a extend approximately perpendicularto the circumferential wall 148 b inward generally toward the centralaxis of the driver column 146. The entire driver column 146, includingthe wings 148, are depicted as hollow, which is a result of the costsavings available by producing the housing 102, including the drivercolumn 146 as an integral, unitary casting. Other embodiments arecontemplated, however. For example, the wings could be solid and/orsecured to the housing in an alternative embodiment.

Each wing 148 defines a mounting boss 150 at its top 152 for receivingfixing hardware for mounting a driver box 200 to be associated with theluminaire 100 during installation. In the depicted embodiment, themounting boss defines a screw hole 154 for receiving a screw, but otherfixing hardware is contemplated in the alternative. The mounting boss152 is limited to the outer portion of each wing 148, leaving a recessedland 156 defined by the four mounting bosses 152.

An aperture 158 is defined at the center of the driver column 146through the land 156 to allow utilities to pass from the luminaire 100to the driver box 200. For example, wiring 160 to provide power to thelight sources passes through the aperture 158 to deliver power from adriver located in the driver box 200 to the light sources.

In an exemplary embodiment, the aperture 158 is designed to allow air topass therethrough, even when the wires 160 are present. Air expands andcontracts as it is heated and cooled, respectively. As discussed above,the seal created by gasket 112 seals the air in the portions of theluminaire 100 inward of the gasket from the ambient environment. Thussealed, the expansion and contraction of this sealed air would createair pressure above or below the ambient air pressure unless that sealedair was somehow vented. If the air pressure of this sealed air were tofall below the ambient air pressure, then the luminaire 100 would tendto try to draw air outside the luminaire, along with any dirt, moisture,etc. into the luminaire. Over time, this could tend to break down theseal created by the gasket 112. Allowing air to pass through the drivercolumn aperture 158 allows the luminaire 100 to breath and prevents theluminaire 100 from trying to draw moisture across the seal created bythe gasket 112.

In one particular exemplary embodiment of the luminaire 100, a breathingtube 162 is run through the aperture 158 along with the wiring 160 and asealant 164 fills the remainder of the aperture 158 so that no moisture,air, dirt, etc. can pass through the aperture unless through thebreathing tube 162. In one embodiment, the sealant 164 is the sameurethane adhesive discussed above. In another embodiment, the sealant164 is an elastomer. Other sealants 164 are contemplated. In yet anotherexemplary embodiment, a cylindrical gland 166 having a sealant 164therein is screwed into threads formed in the aperture 158 and thebreathing tube 162 and wiring 160 are run through the sealant 164, whichforms a tight seal around the breathing tube 162 and wiring 160 toprevent ingress of any dirt, moisture, air, etc. into the luminaire 100.The gland 166 could be a commercially available liquid tight fitting forindividual conductors such as a Conta-Clip brand model PG9, in oneexample. Other embodiments are contemplated. Regardless of how thesealant 164 is provided, the breathing tube 162 is run into the driverbox 200 to prevent rain water, dirt, etc. from entering the breathingtube 162 and running down into the luminaire 100.

The driver box 200 comprises a box having a bottom wall 200 a andperimeter walls 200 b creating an upwardly open box. The driver box 200is closed by a cover plate 202 having a central plate 202 a anddownwardly depending edges 202 b along each side of the central plate202 a to direct water, snow, etc. downward past the opening to thedriver box 200. In one exemplary embodiment, the central plate 202 aextends outward beyond each wall 200 b of the driver box to furtherprevent water, snow, etc. from entering the driver box. The driver boxcomprises mounting hardware to facilitate securing the cover plate 202to the driver box 200. In one embodiment, the driver box 200 comprisesdriver box ears 200 c extending from one or more driver box walls 200 aand defining a hole therein to receive a screw for securing the coverplate 202 to the driver box 200. In the depicted embodiment, driver boxears 200 c extend from two opposing ones of the driver box walls 200 a.By extending the driver box ears 200 c, and thus the hole in the coverplate 202 to accommodate the screws, outward beyond the driver box walls200 a, any rain, snow, etc. falling through the hole in the driver boxcover plate 202 will fall outside of the driver box 200 rather than intothe driver box 200. In one possible embodiment, the driver box ears 200c do not extend as high as the driver box walls 200 a, but fall justshort thereof. This prevents any water that may fall through the screwholes in cover plate 202 from traveling across the driver box ears 200 cand into the driver box. Alternatively, the driver box ears 200 c mayextend as high as the driver box walls 200 a, but have a grooveextending across the driver box ears 200 c between the screw holes andthe driver box wall 200 a.

A stem 204 extends downward from the driver box bottom wall 202 a. Inthe exemplary depicted embodiment, the stem 204 is integrally cast withthe driver box 200, but other options are contemplated. The stem 204 isconfigured to slide over the driver column 146 of the luminaire andaccommodate the driver column 146 within the stem 204. In oneembodiment, the stem comprises a wall 204 a having an inner surfacedefining an opening 204 b to receive the driver column 146. A top 204 cof the opening 204 b may be defined by the driver box bottom wall 202 a(as in the depicted embodiment) or by a separate top 204 c. The openingtop 204 c can be shaped to complement all or portions of the top of thedriver column 146 so that the driver box 200 will sit securely on thedriver column 146. The stem opening top 204 c defines a utilitiesaperture 204 d to accommodate the wiring 160 and the breathing tube 162and gland 166, where present, allowing them to enter the driver box 200.The breathing tube 162 need only enter the driver box 200 and beprotected from the elements by the driver box 200 and cover plate 202.The wiring 160 enters the driver box 200 through the utilities aperture204 d and is connected to a driver (not depicted) for providing power tothe light sources. One or more hardware apertures 204 e are defined inthe top 204 c and configured to allow screws or the like to pass throughand secure into a corresponding one of the screw holes 154 on the drivercolumn 146 to secure the driver box 200 to the driver column 146 and,thus, the luminaire 100.

In one embodiment, the stem wall 204 a defines a lower edge 204 f and agroove 206 about the entirety of the lower edge 204 f. The groove 206accommodates a gasket 208. In the depicted embodiment, the stem wall 204a is cylindrical and the groove 208 and corresponding gasket 208 arecircular. Other embodiments are contemplated.

During installation to a structure 210, the housing 102 is elevated tothe structure and the driver column 146 passed through an aperture 210 ain the structure. The structure 210 could be, by way of example only, aceiling or a canopy for a petroleum refill station. The structureaperture 210 a could be a pre-existing aperture left over from apreviously installed luminaire or it could be a newly constructedaperture. The gasket 208 rests in the groove 206 defined by the stemwall lower edge 204 f and becomes compressed when brought into contactwith the structure and the stem 204 tightly secured to the driver column146. When in this compressed state, the gasket 208 forms a seal aroundthe structure aperture 210 a to prevent material above the structure(e.g. dirt, water, etc.) from getting to the structure aperture 210 a.The ability of the gasket 208 to prevent material from getting to thestructure aperture 210 a in this manner is predicated on the gasket 208and the groove 206, in which is resides, being larger than the structureaperture 210 a. In one exemplary embodiment, the stem wall 204 a issized to allow the gasket 208 to circumscribe at least a 4 inch diameterstructure aperture 210 a, which is commonly left behind by pre-existingluminaires. Other dimensions are also contemplated. While this size stemis larger than necessary for some applications, it has also been foundthat the large size of the stem also assists in providing stability ofthe structure 210 when the structure is somewhat flexible, such as in asheet metal canopy as is often found at a petroleum refill station.

The stem 204 is preferably of a height to elevate the driver box 200, orportions thereof, above the height where water, snow, etc. may beallowed to accumulate. For example, a sheet metal canopy a petroleumrefill station will often accumulate some water and/or snow duringprecipitation before that water is directed off the canopy. The heightof the stem is preferably designed so that the driver box 200 is abovethe height to which water and/or snow are likely to accumulate. In thisembodiment, the driver within the driver box 200 is more likely to bekept dry than if the stem places the driver box 200 below that height.

A mounting apparatus 300 is depicted in FIGS. 7A-7G which can be usedwith the luminaire 100 described above, or with a different luminaire.For continuity, the mounting apparatus 300 of the present disclosurewill be described in conjunction with the luminaire 100 previouslydescribed herein. The mounting apparatus 300 is beneficial in mounting aluminaire, such as luminaire 100, to a mounting structure 302, which maydepend from another structure such as a ceiling or the canopy of apetroleum refill station.

The mounting structure 302 comprises four walls 302 a forming arectangular box, square in the depicted embodiment. The mountingstructure 302 further comprises a face plate 304 extending between thefour walls 302 a slightly above their lower distal ends 302 b. The faceplate 304 lies generally horizontal and defines a face plate aperture306. The face plate 304 can be separate from the walls 302 a or extendintegrally from the walls 302 as depicted in FIG. 7B. The mountingstructure 302 can be a pre-existing mounting structure in which adifferent luminaire had been installed or can be newly constructed forinstallation of a luminaire such as the luminaire 100. However, themounting assembly 300 finds particular use for installing modernLED-based luminaires (such as luminaire 100) in mounting structures suchas mounting structure 302 which is typical for housing older modelluminaires such as HID or incandescent luminaires.

The mounting apparatus 300 comprises a mounting plate 308 mounted to theback of a luminaire, such as luminaire 100. The mounting plate 308optionally defines a mounting plate aperture 308 a to allow portions ofthe luminaire to project through. In the depicted example, the drivercolumn 146 of the previously described luminaire 100 is allowed toproject through the mounting plate 308 due to the aperture 308 a.Flanges 308 b extend upward from each edge of the mounting plate 308 ashort distance to contact, or come close to contacting, the mountingstructure 302 when installed. A hinge flange 308 c extends from a firstof the flanges 308 b and comprises an extending portion 308 c′ and wings308 c″ extending from opposing sides of the extending portion 308″. Theextending portion 308 c′ does not extend to the ends of the first of theflanges 308 b, but instead leaves clearance on both ends. The wings 308c″ extend beyond the ends of the first of the flanges 308 b and beyondthe edges of the corresponding aperture 306 of the mounting structureface plate 304. In this configuration, the luminaire (such as luminaire100) may hang from the mounting structure 302 by the wings 308 c″ andmay rotate about those wings 308 c″. The clearance left on both ends ofthe extending portion 308 c′ provides clearance between the extendingportion and the edges of the corresponding aperture 306 during rotation.During installation, this structure allows an installer to connect thewiring of the luminaire to the power source in the mounting structure302. The mounting plate 308 can be mounted to the luminaire by screws orother hardware.

A catch 310 optionally extends from the mounting plate 308 adjacent to asecond of the flanges 308 b extending from the mounting plate 308 on aside opposite to the first of the flanges 308 b from which the hingeflange 308 c extends. The catch 310 comprises a stem 310 a and a hook310 b extending from the flange. In the depicted embodiment, stem 310 ais mounted to the mounting plate 308 and extend upward to a stem distalend 310 c, while the hook 310 b extends downward from the stem distalend 310 c angled toward the face plate 302 and extending to a hookdistal end 310 d that lies outside of the face plate aperture 306 suchthat when the luminaire 100 is rotated downward from the mountingstructure 302, the hook catches the face plate 304 and prevents theluminaire 100 from rotating further. A person seeking to rotate theluminaire 100 further may bend the stem 310 a inward a distancesufficient to allow the hook distal end 301 d to pass the face plate304. When rotating the luminaire 100 into the mounting structure, theangle of the hook 310 b causes the stem 310 a to deflect inward as thehook 310 b slides past the face plate 304, allowing the hook 310 b topass the face plate 304 and spring back to an unbiased position afterpassing the face plate 304. While the mounting apparatus 300 isbeneficial without the optional catch 310, the catch 310 is preferablefor the above discussed benefits. Other embodiments of a catch are alsocontemplated.

One or more lock wings 312 are optionally mounted to one lock screw 314each, which extends vertically through the luminaire 100 and themounting plate 308 at a location adjacent to the second of the flanges308 b extending from the mounting plate 308 on a side opposite to thefirst of the flanges 308 b from which the hinge flange 308 c extends. Inthe depicted embodiment, the mounting apparatus 300 comprises two lockwings 312, each mounted to one lock screw 314. Each lock screw 314comprises a head 314 a located at the face of the luminaire 100, makingthe head 314 a accessible when the mounting apparatus 300 is in theclosed position depicted in FIGS. 7A, 7B and 7D (i.e. fully mounted tothe mounting structure 302). The lock screw 314 also comprises athreaded shaft 314 b extending through the luminaire 100, through themounting plate 308 and far enough above the mounting plate 308 such thatit extends above the mounting structure face plate 304 when the mountingapparatus 300 is in the closed position.

Each lock wing 312 comprises a lock arm 312 a and a stop arm 312 bconnected by a bridge member 312 c. In the depicted embodiment, the lockwing 312 is constructed of sheet metal bent into a U-shapedconfiguration in which the lock arm 312 a constitutes one leg of the U,the stop arm 312 b constitutes the other leg of the U and the bridgemember 312 c constitutes the base of the U. In the depicted embodiment,an optional strengthening flange 312 d extends along and perpendicularto the lock arm 312 a to provide structural rigidity to the lock arm312. Each of the lock arm 312 a and the stop arm 312 b define a screwaperture 312 e for allowing the screw shaft 314 b to pass through.Optionally, one or both of the screw apertures 312 e is threaded so thatthe lock wing 312 can be threaded onto the screw shaft 314 b.Alternatively, or in addition, the lock wing 312 can be mounted to thescrew shaft 314 b by other means, such as, by way of example only,adhesive.

Each lock wing 312 is mounted on the screw shaft 314 b at a distancefrom the screw head 314 a that will locate the lock arm 312 a slightlyabove the mounting structure face plate 304. In this configuration, eachlock wing 312 can be rotated about the central axis of its correspondingscrew 314 by rotating the screw head 314 a of the corresponding screw314. Rotating the lock wing 312 can bring the lock arm 312 a over themounting structure face plate 304 or over the aperture 306 defined inthe mounting structure face plate 304. When the lock arm 312 a is overthe mounting structure face plate 304, the lock arm 312 a prevents theluminaire 100 from rotating about the wings 308 c″ of the hinge flange308 c, thus keeping the luminaire 100 secure to the mounting structure302. However, when the lock arm 312 a is over the aperture 306 definedin the mounting structure face plate 304, the luminaire 100 may freelyrotate about the wings 308 c″ of the hinge flange 308 c, thus allowingaccess to the luminaire 100 or removal of the luminaire 100 from themounting structure 100 (with the above described manipulation of theoptional catch 310, if present). In this configuration, locking andunlocking the luminaire 100 to the mounting structure 302 requires onlya ninety degree (90°) rotation of the screw head 314 a. The stop arm 312b assists a person seeking to lock the luminaire 100 to the mountingstructure 302 by contacting the adjacent mounting plate flange 308 bbefore the lock arm 312 a has rotated too far. In this manner, the stoparm 312 b stops rotation of the lock wing 312 at the appropriatelocation so that it does not continue rotation and end up over the faceplate aperture 306. In the embodiment in which one or more of the screwapertures 312 e of the lock wing 312 are threaded to the screw shaft 314b, the stop arm 312 b prevents rotation of the lock wing 312 andcontinued advancement of the screw 314 would draw the lock wing 312closer to the screw head 314 a drawing the luminaire 100 closer to themounting structure face plate 304, allowing a person to tighten theluminaire 100 up against the mounting structure face plate 304, or leavean gap there between at the option of the person. FIG. 7B depicts onelock wing 312 in the locked position and one lock wing 312 in theunlocked position. Other configurations and operations of the lock wings312 are contemplated.

Optionally, the driver and/or other utilities can be mounted to themounting plate 308. In the depicted exemplary embodiment, the mountingplate 308 comprises a driver flange 308 d extending upward from themounting plate and the utilities are attached thereto. By extending thedriver flange 308 d upward of the mounting plate, the driver isseparated from the luminaire housing to remove the heat of the utilitiesfrom the housing. The driver flange 308 d may also act as a heatdissipation fin to dispel heat from the luminaire housing into themounting apparatus 300.

FIGS. 7F and 7G depict optional mounting structure extensions 316 a, 316b that may be mounted to the inner edge of the mounting structure faceplate aperture 306 to extend the edges of that aperture 306 inward ifslightly larger than desired for an appropriate fit with the mountingapparatus 300. In operation, the mounting structure extensions 316 a,316 b are slide over the inner edge of the aperture 360 onto the faceplate to provide a new aperture appropriately sized.

The LEDs of this exemplary embodiment can be of any kind, color (e.g.,emitting any color or white light or mixture of colors and white lightas the intended lighting arrangement requires) and luminance capacity orintensity, preferably in the visible spectrum. Color selection can bemade as the intended lighting arrangement requires. In accordance withthe present disclosure, LEDs can comprise any semiconductorconfiguration and material or combination (alloy) that produce theintended array of color or colors. The LEDs can have a refractive opticbuilt-in with the LED or placed over the LED, or no refractive optic;and can alternatively, or also, have a surrounding reflector, e.g., thatre-directs low-angle and mid-angle LED light outwardly. In one suitableembodiment, the LEDs are white LEDs each comprising a gallium nitride(GaN)-based light emitting semiconductor device coupled to a coatingcontaining one or more phosphors. The GaN-based semiconductor device canemit light in the blue and/or ultraviolet range, and excites thephosphor coating to produce longer wavelength light. The combined lightoutput can approximate a white light output. For example, a GaN-basedsemiconductor device generating blue light can be combined with a yellowphosphor to produce white light. Alternatively, a GaN-basedsemiconductor device generating ultraviolet light can be combined withred, green, and blue phosphors in a ratio and arrangement that produceswhite light (or another desired color). In yet another suitableembodiment, colored LEDs are used, such are phosphide-basedsemiconductor devices emitting red or green light, in which case the LEDassembly produces light of the corresponding color. In still yet anothersuitable embodiment, the LED light board may include red, green, andblue LEDs distributed on the printed circuit board in a selected patternto produce light of a selected color using a red-green-blue (RGB) colorcomposition arrangement. In this latter exemplary embodiment, the LEDlight board can be configured to emit a selectable color by selectiveoperation of the red, green, and blue LEDs at selected opticalintensities. Clusters of different kinds and colors of LED is alsocontemplated to obtain the benefits of blending their output.

The various luminaires that have been discussed may be used as outdoorlighting canopies. Each may have within it a single circuit board thatcontains one or more power supplies, drivers, and long chains of lowpower LEDs. Examples of these are described in the following figures andtext that describes them.

FIG. 8 illustrates an example of a circuit that includes a driver 801and a long chain of low power LEDs 803 that may be driven by the driver801, all of which may be on a single circuit board within an outdoorcanopy light.

The driver 801 may be an integrated circuit, such as a DT3001 TB (madeby Seoul Semiconductor). The driver 801 may receive a full waverectified sign wave as input power by connecting the positive side ofthis to input pin 4 and the ground side to input pin 2. This may besupplied, for example, by an AC line voltage that is delivered to aninput connection 804. A fuse 805 may protect the circuit from anoverload. A full wave bridge rectifier 807 may rectify the AC linevoltage. The current that is delivered by the full wave bridge rectifier807 may be limited, such as by resistor pairs 809 and resistor pairs 811in each leg of the rectified voltage which may have a low resistance,such as about 20 ohms each. The rectified and current-limited outputfrom the full wave bridge rectifier 807 may be protected against surgesin the AC line voltage by a transient voltage suppression diode (TVS)813 and/or a metal oxide varistor (MOV) 815. Operating points of thedriver 801 may be set by various components, such as by a R_set resistor815 and a R_bld resistor 817.

The driver 801 may deliver a voltage-stepped, current-regulated outputat its output, such as at its output pins 11, 10, 9, and 8, with anoutput pin 2 serving as a ground reference. The driver 801 may delivercurrent in a voltage-stepped sequence. The first step may provide aground connection at pin 11, the next step at pin 10, the next step atpin 9, and then the final step at pin 8. The voltage may increase ateach step in synchronism with increases in the full wave bridgerectified voltage input on pin 4. The voltage may then step back down,first back to pin 9, then back to pin 10, and then finally back to pin11, again in synchronism with decreases in the full wave bridgerectified input voltage on pin 4. The driver 801 may repeat this steppedup and then stepped down cycle during each rising and falling portion ofeach 180 degree segment of the full wave bridge rectified AC line inputvoltage.

The long chain of low power LEDs 803 may consist of a minimum of 36 or aminimum of 48 low power LEDs connected in series. Each LED may have apower rating that is no more than 1 watt or 0.6 watts. The LEDs may beof any type, such as a Nichia NFSW757D-v1 or NFSL757D-v1. They may emitwhite light or light of any desired color or color combination.

As can be seen in FIG. 8, the long chain of low powered LEDs 803 may bedivided into sub-chains, with each sub chain being driven by one of thestepped outputs from the driver 801. At least one sub-chain may have aminimum of 12 or 16 LEDs connected in series. No sub-chain may have lessthan 6 or 8 LEDs connected in series. Although only one chain of LEDs isshown in FIG. 8, multiple chains of LEDs may instead be connected inparallel to the various outputs of the driver 801, or each additionalchain of LEDs may be connected to a separate driver with separate or(partially or fully) shared support circuitry.

The design illustrated in FIG. 8 and discussed above may not require anyelectrolytic capacitors and thus may not be susceptible to failurescaused by defective electrolytic capacitors when they age.

FIG. 9 illustrates an example of a circuit that includes multipledrivers 801 and 901 and a long chain of low power LEDs 803 that may bedriven by multiple drivers 801 and 901 with their outputs connected inparallel, all of which may be on a single circuit board, all within anoutdoor canopy light. The circuit in FIG. 9 may be identical to the oneshown in FIG. 8, except that the multiple drivers 801 and 901 are beingused to drive the same chain of LEDs (or chains of LEDs if more than onechain of LEDs is connected in parallel). The driver 901 may be the sametype as the driver 801 or different.

As also shown in FIG. 9, the additional driver 901 may have its ownoperating point setting resistors 915 and 917, but otherwise may sharethe power supply and surge suppression components that are also usedwith the driver 801 and described above. Additional drivers and theirassociated operating point setting resistors may be added in parallel inthe same way to provide added current-driving capability, which may beuseful when multiple chains of LEDs are connected in parallel or tomatch the current needs of a single chain of LEDs.

FIG. 10 illustrates an example of a block diagram of an outdoor canopylight 1001 that may use a single full wave bridge rectifier circuitry1013 to supply power to multiple sets of driver circuitry/LED chain(s)1015, 1017, 1019, 1021. The full wave bridge rectifier circuitry 1013may generate a full wave bridge rectified AC signal, such as the onegenerated by the power supply illustrated in FIGS. 8 and 9. The fullwave bridge rectifier circuitry 1013 may include the line voltage inputs804, the fuse 805, and the full wave rectifier bridge rectifier 807).Each of the driver circuitry/LED chain(s) 1015, 1017, 1019, 1021 mayinclude one or more drivers, such as the drivers 801 and/or 901, thecurrent limiting resistor pairs 809 and 811, the voltage suppressiondiode (TVS) 813, the metal oxide varistor (MOV) 815, associatedoperating set point circuitry, such as the R_sets 815 and 915, theR_blds 817 and 917, and one or more long chains of low power LEDs, suchas the long chain of low power LEDs 803. All of the components may againbe on a single circuit board, with the full wave bridge rectifiercircuitry 1013 being in a central areas and each of the multiple sets ofdriver circuitry/LED chain(s) 1015, 1017, 1019, 1021 being in one of thefour quadrants One or more of these components may instead be placed inother locations. Separate full wave bridge rectifier circuitry may alsoinstead be provided for each of the driver circuitry/LED chain(s) or forsub-groups of them. Similarly, a common set of the current limitingresistor pairs 809 and 811, the voltage suppression diode (TVS) 813, andthe metal oxide varistor (MOV) 815 may also instead be used.

FIG. 11 illustrates an example of one quadrant of a long chain of lowpower LEDs on a single circuit board 1101. An example of one of theseLEDs is LED 1103. The light grey area on the circuit board is a foilpattern that may advantageously be used to connect the LEDs in seriesand that provides electrical connections 1105, 1107, 1109, and 1113 tosub-chains within the chain.

FIG. 12 illustrates an example of a single circuit board 1201 that maybe placed within an outdoor canopy light that includes a centralizedarea 1203 which may contain an input connection for the AC line voltageand four quadrants. Each quadrant may include a long chain of low powerLEDs, such as the long chain of low power LEDs 1205, 1207, 1209, or1211. Each quadrant may also include its own power supply, driver(s) andoperational set point components, such as in the areas 1213, 1215, 1217,and 1219 of each quadrant.

Optics may be used to direct the light generated by the LEDs. Separateoptics may be used for each LED or section of LEDs. Or all of the LEDsmay share the same optics. The canopy lights that have been describedmay be used for any purpose, such as for outdoor lighting, such as inparking lots and gas stations.

The components, steps, features, objects, benefits, and advantages thathave been discussed are merely illustrative. None of them, nor thediscussions relating to them, are intended to limit the scope ofprotection in any way. Numerous other embodiments are also contemplated.These include embodiments that have fewer, additional, and/or differentcomponents, steps, features, objects, benefits, and/or advantages. Thesealso include embodiments in which the components and/or steps arearranged and/or ordered differently.

For example, the component values that have been described may be idealwhen the input line voltage is 120 VAC. However, other input linevoltages may be used instead, such as 240 VAC. In this situation, thetypical number of components and/or their values may be adjusted tocompensate for this voltage change, as should readily be apparent tothose skilled in the art. For example, the number or wattage of the LEDsper chain and sub-chain may be doubled.

Unless otherwise stated, all measurements, values, ratings, positions,magnitudes, sizes, and other specifications that are set forth in thisspecification, including in the claims that follow, are approximate, notexact. They are intended to have a reasonable range that is consistentwith the functions to which they relate and with what is customary inthe art to which they pertain.

All articles, patents, patent applications, and other publications thathave been cited in this disclosure are incorporated herein by reference.

The phrase “means for” when used in a claim is intended to and should beinterpreted to embrace the corresponding structures and materials thathave been described and their equivalents. Similarly, the phrase “stepfor” when used in a claim is intended to and should be interpreted toembrace the corresponding acts that have been described and theirequivalents. The absence of these phrases from a claim means that theclaim is not intended to and should not be interpreted to be limited tothese corresponding structures, materials, or acts, or to theirequivalents.

The scope of protection is limited solely by the claims that now follow.That scope is intended and should be interpreted to be as broad as isconsistent with the ordinary meaning of the language that is used in theclaims when interpreted in light of this specification and theprosecution history that follows, except where specific meanings havebeen set forth, and to encompass all structural and functionalequivalents.

Relational terms such as “first” and “second” and the like may be usedsolely to distinguish one entity or action from another, withoutnecessarily requiring or implying any actual relationship or orderbetween them. The terms “comprises,” “comprising,” and any othervariation thereof when used in connection with a list of elements in thespecification or claims are intended to indicate that the list is notexclusive and that other elements may be included. Similarly, an elementpreceded by an “a” or an “an” does not, without further constraints,preclude the existence of additional elements of the identical type.

None of the claims are intended to embrace subject matter that fails tosatisfy the requirement of Sections 101, 102, or 103 of the Patent Act,nor should they be interpreted in such a way. Any unintended coverage ofsuch subject matter is hereby disclaimed. Except as just stated in thisparagraph, nothing that has been stated or illustrated is intended orshould be interpreted to cause a dedication of any component, step,feature, object, benefit, advantage, or equivalent to the public,regardless of whether it is or is not recited in the claims.

The abstract is provided to help the reader quickly ascertain the natureof the technical disclosure. It is submitted with the understanding thatit will not be used to interpret or limit the scope or meaning of theclaims. In addition, various features in the foregoing detaileddescription are grouped together in various embodiments to streamlinethe disclosure. This method of disclosure should not be interpreted asrequiring claimed embodiments to require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus, the following claims are herebyincorporated into the detailed description, with each claim standing onits own as separately claimed subject matter.

The invention claimed is:
 1. A luminaire comprising: a housing; an inputconnection within the housing that receives AC line voltage; multiplechains of LEDs within the housing, each chain containing at least 36LEDs connected in series, and each LED having a power rating of no morethan 1 watt and oriented to direct light outside of the housing whenilluminated; and multiple LED drivers within the housing that receivepower that is extracted from AC line voltage connected to the inputconnection and provide one or more outputs that drive each of the LEDswithin the multiple chains of LEDs.
 2. The luminaire of claim 1 wherein:each chain of LEDs is comprised of multiple sub-chains of LEDs connectedin series, each sub-chain containing multiple LEDs in series; and eachof the LED drivers provide a separate output that drives at least one ofthe chains of LEDs at each of the junctions between each of itssub-chains in a stepped sequence that is a function of the level ofvoltage of the power that is received by LED driver.
 3. The luminaire ofclaim 2 wherein at least one sub-chain within each chain includes atleast 12 LEDs.
 4. The luminaire of claim 3 wherein no sub-chain withineach chain includes less than 6 LEDs.
 5. The luminaire of claim 2wherein the outputs of at least two of the LED drivers are connected inparallel.
 6. The luminaire of claim 2 wherein the outputs of at leastone of the LED drivers is connected to one of the chains of LEDs and theoutputs of at least one other of the LED drivers is connected to anotherof the chains of LEDs.
 7. The luminaire of claim 1 wherein the inputconnection, the multiple chains of LEDs, and the multiple LED driversare all on a single printed circuit board.
 8. The luminaire of claim 1wherein each chain has at least 48 LEDs.
 9. The luminaire of claim 1wherein the power rating of each LED is no more than 0.6 watt.
 10. Theluminaire of claim 1 wherein the housing forms a canopy light.
 11. Aluminaire comprising: a housing; an input connection within the housingthat receives AC line voltage; at least one chain of LEDs within thehousing containing at least 36 LEDs connected in series, each LED havinga power rating of no more than 1 watt and oriented to direct lightoutside of the housing when illuminated; and at least one LED driverwithin the housing that receives power that is extracted from AC linevoltage connected to the input connection and provides one or moreoutputs that drive the chain of LEDs.
 12. The luminaire of claim 11wherein: the chain of LEDs is comprised of multiple sub-chains of LEDsconnected in series, each sub-chain containing multiple LEDs in series;and the at least one driver provides a separate output that drives theat least one chain of LEDs at each of the junctions between each of itssub-chains in a stepped sequence that is a function of the level ofvoltage of the power that is received by LED driver.
 13. The luminaireof claim 12 wherein at least one sub-chain within the at least one chainincludes at least 12 LEDs.
 14. The luminaire of claim 13 wherein nosub-chain within the at least one chain includes less than 6 LEDs. 15.The luminaire of claim 11 wherein the at least one driver includes atleast two drivers whose outputs are connected in parallel.
 16. Theluminaire of claim 11 wherein the input connection, at least one chainof LEDs, and the at least one driver are all on a single printed circuitboard.
 17. The luminaire of claim 11 wherein the at least one chain hasat least 48 LEDs.
 18. The luminaire of claim 11 wherein the power ratingof each LED is no more than 0.6 watt.
 19. The luminaire of claim 11wherein the housing forms a canopy light.
 20. A luminaire comprising: ahousing; an input connection within the housing that receives AC linevoltage; at least one chain of LEDs within the housing containingmultiple LEDs connected in series, each LED oriented to direct lightoutside of the housing when illuminated; and multiple LED drivers withinthe housing that receive power that is extracted from AC line voltageconnected to the input connection and provide one or more outputs thatdrive each of the LEDs within the at least one chain of LEDs.
 21. Theluminaire of claim 20 wherein: the at least one chain of LEDs iscomprised of multiple sub-chains of LEDs connected in series, eachsub-chain containing multiple LEDs in series; and each of the driversprovides a separate output that drives the at least one chain of LEDs ateach of the junctions between each of its sub-chains in a steppedsequence that is a function of the level of voltage of the power that isreceived by LED drivers.
 22. The luminaire of claim 21 wherein theoutputs of at least two of the drivers are connected in parallel. 23.The luminaire of claim 21 wherein the outputs of at least two of thedrivers are connected to different chains of LEDs.
 24. The luminaire ofclaim 20 wherein the input connection, the at least one chain of LEDs,and the multiple LED drivers are all on a single printed circuit board.25. The luminaire of claim 20 wherein the housing forms a canopy light.26. A luminaire comprising: a housing; an input connection within thehousing that receives AC line voltage; a chain of LEDs within thehousing containing multiple LEDs connected in series, each oriented todirect light outside of the housing when illuminated; and multiple LEDdrivers within the housing, each of which receive power that isextracted from AC line voltage connected to the input connection andprovide an output that drives each of the LEDs within the chain of LEDs,each of the outputs being connected in parallel.
 27. The luminaire ofclaim 26 wherein each LED driver provides multiple stepped outputs atdifferent step levels and wherein each stepped output is connected inparallel with all of the other stepped outputs from the other LEDdrivers at the same step level.